359 hours on the hobbs - Right elevator frame riveted!

Man I love it when I am able to rivet a frame together without botching it up somewhere along the way. I think the biggest contributing factor to my success was the fact that I finall ground down all my yokes so that they would not interfere with the parts, and I also established a pattern of bucking the AN 470 rivets SLOWLY so that I could check the rivet shank for signs of clinching or other problems and correct them early before the rivet was set all the way. I did not have to drill out a single rivet on the frame. Truly cause for celebration!

Ok, so more pics:
Here is one side of the control horn all riveted in place:

And a wider shot of how I clamped it all down so that everything was solid and non-moving during the riveting.

Also in the above pic was my "Fat Man" tungsten bucking bar. I used the angle part of the par to get into the inside corner of the joint between the rib and spar. The two rivets closest to the inside edge were very tricky. I ahd to hold the bar in just the right attitude, position the fingers of my left hand to ensure that the bottom of the bar would not strike either the spar web or the rib web depending on which rivet I was bucking. I also used my rivet cutter to trim some AN470AD4-6 rivets down to the proper size by using my ruler to adjust the cut to just the right length. Next pic shows the rivet shaft at the correct length. Van's calls for 4-4 rivets here and they are just too short, and a 4-5 rivet is just too long.

And here is the outside of the control horn, riveted in place on both sides. I wanted to make sure the rivets were the correct size here because this horn attaches to both the center hinge bearing on the HS and also to the end of the pushrod that ultimately attaches to the control stick. So this is an area that will be exercised by both movement and force for the life of the plane, and so it needs to be as solid as possible.

And the inside shot

Next comes the attachment of the counterweight skin to the elevator skin. You have to do it this way if you want to set four of the rivets with solid rivets. If you don't, then you have to use pop rivets for these holes because the ribs will close off the area where these holes reside, and you cannot get a squeezer or bucking bar in that area once the frame is in place.

to set the rivets (2 on each side), I used my hand squeezer. Before doing so I decided to take it to the grinder based on a post I read a long while back. I was tired of being told that this is the tool that everyone uses for close quarter riveting, when my experience had been that the taper of the yoke was still so wide that you cannot get it into these tight places. I printed out a post that I found that describes a method to take a C clamp and grind it down so that you insert into a tight fitting area to buck or squeeze a rivet. The process was the same for the yoke - just grind down the tip of the yoke far enough to be able to insert it where you need it, and squeeze away. I am probably not done refining it yet, but you get the idea of what I trying to do from the photo: Notice the "notch" about an inch back from the tip where I have flattened it out.

This actually worked well for the flush rivets I had to set to attach the root rib to the spar prior to attaching the control horn. Next is a method I used to set the 4 solid rivets on the counterweight skin that I mentioned before. I used one of my cleco clamps and no hole yoke pictured above to set all four of the rivets.You have to remove the clecoes in order to get the squeezer far enough in there to set the rivets, so to keep the skins together to ensure a good fit I used the cleco clamp

With the counterweight skin riveted in place, it was time to prep the skin with the ceremonial blue RTV/Syringe exercise, similar to what I did for the rudder before riveting it together.

To get the rest of the frame inserted into the skin was a bit of a chore. I enlisted the help of my good friend and neighbor, Kevin Shepard, to help get things into position so I could cleco everything in place. Once you squeeze the RTV on the ends of the stiffeners, you have about a half hour to get everything in place before it starts to set up and harden. The trick is that you have to hold the lead counterweight against the counterweight skin that we just riveted in place, while the end ribs of the frame are inserted behind the weight, and then the entire frame is swung into the correct position so that the ribs line up with the holes in the skin. Having an extra pair of hands for this was definitely helpful. Here is the assembly all swung into place and clecoed together for final riveting:

So, now we are all ready to rivet, right? Uh, not so fast. After getting to this point I realized something. Steve Riffe has pics of this step in his log, and I kept seeing two copper colored clecoes in two of the holes on the top and bottom of the tip of the elevator, which indicates that the holes were drilled to 1/8 inch diameter. In my haste to assemble the frame, I neglected to pay enough attention to the area outside of the end ribs where the coungterweight skin, the rib, and the elevator skin all overlap. I thought I could leave all the holes for the fiberglass tips alone until I was ready to fit and attach them later on.

The problem is that the counterweight skin has two holes that overlap then ends of elevator skin where the attach holes fo the tips are located. Therefore those holes need to be dimpled to accept the correct size rivet or screw head, depending on your preferred method of attaching the fiberglass tips. I have decided to use #6 screws and nut plates as discussed in this forum post on VAF so that I can rmove or replace the tips as needed. This is very desireable for the wing tips due to all the wiring for lights and such that may require periodic maintenance, and thus removal of the tips from time to time, and I want to be able repair or replace the fiberglass stuff as quickly as easily as possible.

Regardless of the decision to rivet or screw, you still need to DIMPLE the holes, which I obviously forgot to do. So, all that careful slipping and sliding of the frame into the skin was all for not. I have to drill out the four flush rivets holding the counterweight on, and then uncleco the entire skin and remove the frame so I can dimple 4 lousy holes in the counterweight skin and the elevator skin. I am going to use #6 screws for this so I will need to use a #6 dimple die, after drilling the hole with the #28 drill bit. I just have to be careful not to break the seal from the RTV when I remove and replace the frame after I dimple the holes. DANG IT! And I was doing so well....